Solid Lubricated Tribological Experiment on Behaviors of Wear Debris in Microgravity aboard the Chinese New-Generation Manned Spaceship

Lasting spacecraft and long-term space mission need reliable lubricants and lubrication technology. In space applications, solid lubricants outperform liquid lubricants in temperature resistance, radiation resistance, and so on. But solid lubricants are not panacea, because the friction products, wear debris, may be detrimental to some delicate components like cameras. Therefore, the collection and management of wear debris is indispensable. In order to figure out the behaviors of wear debris to perform the collection and management, Tribological Experiment Rig (TER) is designed to conduct the experiments on orbit, microgravity environment, aboard the Chinese new-generation manned spaceship. The TER performs well on orbit and returns successfully, with plenty of pictures recording the behaviors of wear debris. We preliminarily analyze the results and compare it with the results on earth under different gravity states and medium conditions. Result under microgravity environment has no significant difference to the gravitational result at atmosphere but it is much different to the gravitational result in vacuum. It implies that the influence of medium is much obvious than the microgravity and the distribution of wear debris in microgravity could be estimated by experiment on earth. The result is instructive to engineering applications in microgravity environment. But the equation of motion of wear debris, especially among the air medium, could not be explicit based on so-far experiments. Also, further research is needy for better knowledge about behaviors of wear debris and settling the problems we have met.